Endoscopic cutting forceps with jaw clamp lever latching mechanism

ABSTRACT

A lever latching system comprising: a housing; a lever having a latch pin fixedly mounted to the lever, the lever being movably mounted to the housing so that the latch pin moves in an arc; and a latch plate movably mounted to the housing for linear movement with respect to the housing, the latch plate comprising a labyrinth for receiving the latch pin.

REFERENCE TO PENDING PRIOR PATENT APPLICATION

This patent application claims benefit of pending prior U.S. ProvisionalPatent Application Ser. No. 61/994,179, filed May 16, 2014 by GyrusACMI, Inc. (d.b.a. Olympus Surgical Technologies America) and Dennis G.Lamser et al. for ENDOSCOPIC CUTTING FORCEPS WITH JAW CLAMP LEVERLATCHING MECHANISM (Attorney's Docket No. OLYMPUS-1 PROV), which patentapplication is hereby incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to surgical apparatus and methods in general, andmore particularly to endoscopic cutting forceps and jaw clamp leverlatching mechanisms for use with the same and/or for use with otherlever-actuated devices.

BACKGROUND OF THE INVENTION

Endoscopic cutting forceps are well known in the art. In general,endoscopic cutting forceps comprise a pair of jaws disposed at thedistal end of a shaft, a blade cutter configured to reciprocate in thespace between the jaws (and hence cut tissue disposed between the pairof jaws), and a handle disposed at the proximal end of the shaft forcarrying a lever for actuating the pair of jaws and a trigger foractuating the blade cutter. In some constructions, the endoscopiccutting forceps allow the pair of jaws and the blade cutter to berotated as a unit about the axis of the shaft, and/or the endoscopiccutting forceps allow the pair of jaws to be electrically energized soas to provide electrocautery function to the endoscopic cutting forceps.

In general, it can be convenient to provide a latching mechanism for thelever which actuates the jaws, whereby to allow the jaws to betemporarily locked (or clamped) in a closed position about tissue, e.g.,while the blade cutter is actuated to cut the tissue disposed betweenthe clamped jaws.

Unfortunately, current latching mechanisms for endoscopic cuttingforceps tend to be mechanically complex and hence difficult and/orexpensive to manufacture.

Thus there is a need for a new and improved latching mechanism for anendoscopic cutting forceps wherein the latching mechanism ismechanically simple and hence easy and inexpensive to manufacture.

There is also a need for a new and improved latching mechanism for theactuating levers of other surgical instruments and/or otherlever-actuated devices wherein the latching mechanism is mechanicallysimple and hence easy and inexpensive to manufacture.

SUMMARY OF THE INVENTION

The present invention provides a new and improved latching mechanism foran endoscopic cutting forceps wherein the latching mechanism ismechanically simple and hence easy and inexpensive to manufacture.

The present invention also provides a new and improved latchingmechanism for the actuating levers of other surgical instruments and/orother lever-actuated devices wherein the latching mechanism ismechanically simple and hence easy and inexpensive to manufacture.

In one form of the present invention, there is provided a lever latchingsystem comprising:

a housing;

a lever having a latch pin fixedly mounted to said lever, said leverbeing movably mounted to said housing so that said latch pin moves in anarc; and

a latch plate movably mounted to said housing for linear movement withrespect to said housing, said latch plate comprising a labyrinth forreceiving said latch pin.

In another form of the present invention, there is provided a leverlatching system comprising:

a housing;

a lever pivotally mounted to said housing at a pivot point, and a latchpin fixedly mounted to said lever at a location offset from said pivotpoint; and

a latch plate movably mounted to said housing for linear movement withrespect to said housing, said latch plate comprising a labyrinth forreceiving said latch pin.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit;

a second unit comprising a latch pin, said second unit being movablymounted to said first unit so that said latch pin moves in a prescribedmotion;

a selector plate movably mounted to said first unit; and

a latch plate comprising a labyrinth for selectively receiving saidlatch pin, said latch plate being movably mounted to said selectorplate;

wherein said latch plate moves linearly relative to said selector plate.

In another form of the present invention, there is provided a latchingsystem comprising:

a first member;

a second member comprising a latch pin, said second member being movablymounted to said first member so that said latch pin moves in aprescribed motion;

a selector plate movably mounted to said first member;

a latch plate movably mounted to a selector plate and comprising alabyrinth for selectively receiving said latch pin;

a spring secured to said selector plate and engaging said latch platefor biasing said latch plate with respect to said selector plate;

wherein said selector plate moves said latch plate between an engagedposition wherein said labyrinth intersects said prescribed motion and adisengaged position wherein said labyrinth does not intersect saidprescribed motion.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit;

a second unit comprising a latch pin, said second unit being movablymounted to said first unit so that said latch pin moves in a prescribedmotion;

a selector plate movably mounted to said first unit; and

a latch plate comprising a labyrinth for selectively receiving saidlatch pin, said latch plate being movably mounted to said selectorplate;

wherein said latch plate comprises an integral spring for biasing saidlatch plate relative to said selector plate.

In another form of the present invention, there is provided a latchingsystem comprising:

a first component comprising a latching pin movable in a prescribedmotion; and

a second component comprising a selector plate that moves a latch platehaving a labyrinth between an engaged position wherein said labyrinthintersects said prescribed motion and a disengaged position wherein saidlabyrinth does not intersect said prescribed motion, said secondcomponent comprising a latch spring secured to said selector plate forbiasing said latch plate with respect to said selector plate.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit;

a second unit;

said first unit and said second unit being movably mounted relative toone another;

a latch pin fixedly mounted to one of said first unit and said secondunit; and

a latch plate movably mounted to the other of said first unit and saidsecond unit for linear movement with respect to said other of said firstunit and said second unit, said latch plate comprising a labyrinth forreceiving said latch pin.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit fixedly mounted to a handpiece;

a second unit;

said first unit and said second unit being movably mounted relative toone another;

a latch pin fixedly mounted to one of said first unit and said secondunit; and

a latch plate movably mounted to the other of said first unit and saidsecond unit for linear movement with respect to said other of said firstunit and said second unit, said latch plate comprising a labyrinth forreceiving said latch pin.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit;

a second unit pivotably mounted to the first unit;

a latch pin fixedly mounted to one of said first unit and said secondunit; and

a latch plate movably mounted to the other of said first unit and saidsecond unit for linear movement with respect to said other of said firstunit and said second unit, said latch plate comprising a labyrinth forreceiving said latch pin.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit;

a second unit;

said first unit and said second unit being movably mounted relative toone another;

a latch pin fixedly mounted to one of said first unit and said secondunit; and

a latch plate movably mounted to the other of said first unit and saidsecond unit for non-linear and non-pivotal movement with respect to saidother of said first unit and said second unit, said latch platecomprising a labyrinth for receiving said latch pin.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit;

a second unit;

said first unit and said second unit being movably mounted relative toone another;

a latch pin fixedly mounted to one of said first unit and said secondunit; and

a latch plate movably mounted to the other of said first unit and saidsecond unit for non-pivotal movement with respect to said other of saidfirst unit and said second unit, said latch plate comprising a labyrinthfor receiving said latch pin.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a lever latching system comprising:

-   -   a housing connected to the mechanism to be operated;    -   a lever connected to the mechanism to be operated and pivotally        mounted to said housing at a pivot point, and a latch pin        fixedly mounted to said lever at a location offset from said        pivot point; and    -   a latch plate movably mounted to said housing for linear        movement with respect to said housing, said latch plate        comprising a labyrinth for receiving said latch pin;

moving said lever so that said latch pin causes said latch plate to movewith respect to said housing so that said latch pin is disposed at alatched position within said labyrinth, whereby to cause the mechanismto transition from its first state to its second state and maintain themechanism in its second state; and

moving said lever so that said latch pin moves out of latched positionwithin said labyrinth, whereby to cause the mechanism to transition fromits second state to its first state.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a lever latching system comprising:

-   -   a housing connected to the mechanism to be operated;    -   a lever connected to the mechanism to be operated and having a        latch pin fixedly mounted to said lever, said lever being        movably mounted to said housing so that said latch pin moves in        an arc; and    -   a latch plate movably mounted to said housing for linear        movement with respect to said housing, said latch plate        comprising a labyrinth for receiving said latch pin;

moving said lever so that said latch pin causes said latch plate to movewith respect to said housing so that said latch pin is disposed at alatched position within said labyrinth, whereby to cause the mechanismto transition from its first state to its second state and maintain themechanism in its second state; and

moving said lever so that said latch pin moves out of its latchedposition within said labyrinth, whereby to cause the mechanism totransition from its second state to its first state.

In another form of the present invention, there is provided a method foroperating a mechanism having a state and a second state, the methodcomprising:

providing a latching system comprising:

-   -   a first unit connected to the mechanism to be operated;    -   a second unit connected to the mechanism to be operated and        comprising a latch pin, said second unit being movably mounted        to said first unit so that said latch pin moves in a prescribed        motion;    -   a selector plate movably mounted to said first unit; and    -   a latch plate comprising a labyrinth for selectively receiving        said latch pin, said latch plate being movably mounted to said        selector plate;    -   wherein said latch plate moves linearly relative to said        selector plate;

moving said second unit so that said latch pin causes said latch plateto move with respect to said first unit so that said latch pin isdisposed at a latched position within said labyrinth, whereby to causethe mechanism to transition from its first state to its second state andmaintain the mechanism in its second state; and

moving said second unit so that said latch pin moves out of its latchedposition within said labyrinth, whereby to cause the mechanism totransition from its second state to its first state.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first unit connected to the mechanism to be operated;    -   a second unit connected to the mechanism to be operated and        comprising a latch pin, said second unit being movably mounted        to said first unit so that said latch pin moves in a prescribed        motion;    -   a selector plate movably mounted to said first unit; and    -   a latch plate comprising a labyrinth for selectively receiving        said latch pin, said latch plate being movably mounted to said        selector plate;    -   wherein said latch plate comprises an integral spring for        biasing said latch plate relative to said selector plate;

moving said second unit so that said latch pin causes said latch plateto move with respect to said first unit so that said latch pin isdisposed at a latched position within said labyrinth, whereby to causethe mechanism to transition from its first state to its second state andmaintain the mechanism in its second state; and

moving said second unit so that said latch pin moves out of its latchedposition within said labyrinth, whereby to cause the mechanism totransition from its second state to its first state.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first member connected to the mechanism to be operated;    -   a second member connected to the mechanism to be operated and        comprising a latch pin, said second member being movably mounted        to said first member so that said latch pin moves in a        prescribed motion;    -   a selector plate movably mounted to said first member;    -   a latch plate movably mounted to a selector plate and comprising        a labyrinth for selectively receiving said latch pin;    -   a spring secured to said selector plate and engaging said latch        plate for biasing said latch plate with respect to said selector        plate;    -   wherein said selector plate moves said latch plate between an        engaged position wherein said labyrinth intersects said        prescribed motion and a disengaged position wherein said        labyrinth does not intersect said prescribed motion;

moving said second member so that said latch pin causes said latch plateto move with respect to said first member so that said latch pin isdisposed at a latched position within said labyrinth, whereby to causethe mechanism to transition from its first state to its second state andmaintain the mechanism in its second state; and

moving said second member so that said latch pin moves out of itslatched position within said labyrinth, whereby to cause the mechanismto transition from its second state to its first state.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first component connected to the mechanism to be operated and        comprising a latching pin movable in a prescribed motion; and    -   a second component connected to the mechanism to be operated and        comprising a selector plate that moves a latch plate having a        labyrinth between an engaged position wherein said labyrinth        intersects said prescribed motion and a disengaged position        wherein labyrinth does not intersect said prescribed motion,        said second component comprising a latch spring secured to said        selector plate for biasing said latch plate with respect to said        selector plate;

moving said first component so that said latching pin causes said latchplate to move with respect to said second component so that saidlatching pin is disposed at a latched position within said labyrinth,whereby to cause the mechanism to transition from its first state to itssecond state and maintain the mechanism in its second state; and

moving said first component so that said latching pin moves out of itslatched position within said labyrinth, whereby to cause the mechanismto transition from its second state to its first state.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first unit connected to the mechanism to be operated;    -   a second unit connected to the mechanism to be operated;    -   said first unit and said second unit being movably mounted        relative to one another;    -   a latch pin fixedly mounted to one of said first unit and said        second unit; and    -   a latch plate movably mounted to the other of said first unit        and said second unit for linear movement with respect to said        other of said first unit and said second unit, said latch plate        comprising a labyrinth for receiving said latch pin;

moving one of said first unit and said second unit so that said latchpin causes said latch plate to move with respect to the other of saidfirst unit and said second unit so that said latch pin is disposed at alatched position within said labyrinth, whereby to cause the mechanismto transition from its first state to its second state and maintain themechanism in its second state; and

moving one of said first unit and said second unit so that said latchpin moves out of its latched position within said labyrinth, whereby tocause the mechanism to transition from its second state to its firststate.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first unit connected to the mechanism to be operated and        fixedly mounted to a handpiece;    -   a second unit connected to the mechanism to be operated;    -   said first unit and said second unit being movably mounted        relative to one another;    -   a latch pin fixedly mounted to one of said first unit and said        second unit; and    -   a latch plate movably mounted to the other of said first unit        and said second unit for linear movement with respect to said        other of said first unit and said second unit, said latch plate        comprising a labyrinth for receiving said latch pin;

moving one of said first unit and said second unit so that said latchpin causes said latch plate to move with respect to the other of saidfirst unit and said second unit so that said latch pin is disposed at alatched position within said labyrinth, whereby to cause the mechanismto transition from its first state to its second state and maintain themechanism in its second state; and

moving one of said first unit and said second unit so that said latchpin moves out of latched position within said labyrinth, whereby tocause the mechanism to transition from its second state to its firststate.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first unit connected to the mechanism to be operated;    -   a second unit connected to the mechanism to be operated and        pivotably mounted to the first unit;    -   a latch pin fixedly mounted to one of said first unit and said        second unit; and    -   a latch plate movably mounted to the other of said first unit        and said second unit for linear movement with respect to said        other of said first unit and said second unit, said latch plate        comprising a labyrinth for receiving said latch pin;

moving one of said first unit and said second unit so that said latchpin causes said latch plate to move with respect to the other of saidfirst unit and said second unit so that said latch pin is disposed at alatched position within said labyrinth, whereby to cause the mechanismto transition from its first state to its second state and maintain themechanism in its second state; and

moving one of said first unit and said second unit so that said latchpin moves out of its latched position within said labyrinth, whereby tocause the mechanism to transition from its second state to its firststate.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first unit connected to the mechanism to be operated;    -   a second unit connected to the mechanism to be operated;    -   said first unit and said second unit being movably mounted        relative to one another;    -   a latch pin fixedly mounted to one of said first unit and said        second unit; and    -   a latch plate movably mounted to the other of said first unit        and said second unit for non-linear and non-pivotal movement        with respect to said other of said first unit and said second        unit, said latch plate comprising a labyrinth for receiving said        latch pin;

moving one of said first unit and said second unit so that said latchpin causes said latch plate to move with respect to the other of saidfirst unit and said second unit so that said latch pin is disposed at alatched position within said labyrinth, whereby to cause the mechanismto transition from its first state to its second state and maintain themechanism in its second state; and

moving one of said first unit and said second unit so that said latchpin moves out of its latched position within said labyrinth, whereby tocause the mechanism to transition from its second state to its firststate.

In another form of the present invention, there is provided a method foroperating a mechanism having a first state and a second state, themethod comprising:

providing a latching system comprising:

-   -   a first unit connected to the mechanism to be operated;    -   a second unit connected to the mechanism to be operated;    -   said first unit and said second unit being movably mounted        relative to one another;    -   a latch pin fixedly mounted to one of said first unit and said        second unit; and    -   a latch plate movably mounted to the other of said first unit        and said second unit for non-pivotal movement with respect to        said other of said first unit and said second unit, said latch        plate comprising a labyrinth for receiving said latch pin;

moving one of said first unit and said second unit so that said latchpin causes said latch plate to move with respect to the other of saidfirst unit and said second unit so that said latch pin is disposed at alatched position within said labyrinth, whereby to cause the mechanismto transition from its first state to its second state and maintain themechanism in its second state; and

moving one of said first unit and said second unit so that said latchpin moves out of its latched position within said labyrinth, whereby tocause the mechanism to transition from its second state to its firststate.

In another form of the present invention, there is provided a latchingsystem comprising:

a first unit;

a second unit comprising a latch pin, said second unit being movablymounted to said first unit so that said latch pin moves in a prescribedmotion;

a selector plate movably mounted to said first unit; and

a latch plate comprising a labyrinth for selectively receiving saidlatch pin, said latch plate being movably mounted to said selectorplate;

wherein said latch plate comprises an integral spring for biasing saidlatch plate relative to said first unit.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and features of the present invention will bemore fully disclosed or rendered obvious by the following detaileddescription of the preferred embodiments of the invention, which is tobe considered together with the accompanying drawings wherein likenumbers refer to like parts, and further wherein:

FIGS. 1-26 are schematic views showing a novel endoscopic cuttingforceps formed in accordance with the present invention, wherein thenovel endoscopic cutting forceps comprise a novel jaw clamp leverlatching mechanism formed in accordance with the present invention, withFIGS. 1-16 generally showing the general features of the novelendoscopic cutting forceps and FIGS. 17-26 generally showing the noveljaw clamp lever latching mechanism of the novel endoscopic cuttingforceps; and

FIGS. 27-38 are schematic views showing exemplary operation of the noveljam clamp lever latching mechanism of the endoscopic cutting forceps ofFIGS. 1-26 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Looking first at FIGS. 1-4 , there is shown novel endoscopic cuttingforceps 5 which comprise one preferred embodiment of the presentinvention.

The Novel Endoscopic Cutting Forceps in General

Endoscopic cutting forceps 5 generally comprise a pair of jaws 10disposed at the distal end of a shaft 15, a blade cutter 20 configuredto reciprocate in the space between jaws 10 (and hence cut tissuedisposed between the pair of jaws), and a handle 25 disposed at theproximal end of shaft 15 for carrying a lever 30 for actuating the pairof jaws 10 and a trigger 35 for actuating blade cutter 20. Endoscopiccutting forceps 5 preferably allow the pair of jaws 10 and blade cutter20 to be rotated as a unit about the axis of shaft 15 via a knob 40, andendoscopic cutting forceps 5 preferably allow the pair of jaws 10 to beelectrically energized via a button 45 so as to provide electrocauteryfunction to endoscopic cutting forceps 5.

More particularly, and looking now at FIGS. 1-9 , jaws 10 are eachsecured to the distal end 50 of a support rod 55, with support rods 55and the proximal ends of jaws 10 being disposed within shaft 15. Theproximal ends 60 of support rods 55 are secured to a hub 65, which isitself secured to a wall 70 of handle 25. As a result of thisconstruction, jaws 10 are effectively fixed to handle 25. As seen in thefigures, jaws 10 are outwardly biased relative to support rods 55, sothat the distal ends of jaws 10 naturally diverge from one another. Jaws10 comprise slots 75 (FIG. 4 ) which receive blade cutter 20.

Shaft 15 is movable relative to handle 25 so as to selectively closedown jaws 10. More particularly, shaft 15 is hollow and is disposedcoaxially over the proximal ends of jaws 10 and coaxially over supportrods 55. The proximal end of shaft 15 is connected to a mount 80 (FIG. 6) which is engaged by lever 30 as will hereinafter be discussed. Shaft15 has a flange 85 intermediate its length. A compression spring 90 isdisposed about shaft 15 between a wall 95 of handle 25 and flange 85 ofshaft 15 so as to spring-bias shaft 15 in the proximal direction.Another compression spring 100 may be disposed about shaft 15 betweenflange 85 of shaft 15 and a surface of mount 80 so as to bias mount 80proximally.

As noted above, lever 30 may be used to actuate jaws 10. Moreparticularly, lever 30 is rotatably pinned at 105 to handle 25 so thatwhen the finger grip 110 of lever 30 is pulled proximally toward palmgrip 115 of handle 25, the opposing end 120 of lever 30 is moveddistally, whereby to move mount 80 distally and thereby move shaft 15distally. Such distal movement of shaft 15 forces jaws 10 to close. Whenfinger grip 110 of lever 30 is released, compression spring 90 returnsshaft 15 proximally, whereby to cause jaws 10 to open. Note that bladecutter 20 is received in slots 75 of jaws 10 when jaws 10 are in theiropen position and blade cutter 20 is also received in slots 75 of jaws10 when jaws 10 are in their closed position.

Looking now at FIGS. 1-8, 10 and 11 , blade cutter 20 is disposed at thedistal end 125 of a drive rod 130, with the proximal end of blade cutter20 and drive rod 130 being disposed within shaft 15. The proximal end ofdrive rod 130 is secured to a hub 135.

Trigger 35 actuates blade cutter 20. More particularly, trigger 35 isrotatably pinned at 140 to handle 25 so that when trigger 35 is pulledproximally toward palm grip 115 of handle 25, the opposing end 145 oftrigger 35 is moved distally, whereby to move hub 135 distally andthereby move drive rod 130 and blade cutter 20 distally. Note that whenjaws 10 are in their closed position and blade cutter 20 is moveddistally, blade cutter 20 will ride distally within slots 75 formed injaws 10.

As noted above, endoscopic cutting forceps 5 preferably allow the pairof jaws 10 and blade cutter 20 to be rotated as a unit about the axis ofshaft 15 via a knob 40. To this end, knob 40 drivingly engages mount 80such that when knob 40 is rotated, mount 80 is also rotated, whereby torotate hub 65 and thereby rotate support rods 55 and hence jaws 10. Notethat inasmuch as blade cutter 20 is received within slots 75 in jaws 10when jaws 10 are in both their open and closed positions, rotation ofjaws 10 will cause blade cutter 20 to rotate in unison with jaws 10.

As also noted above, endoscopic cutting forceps 5 allow the pair of jaws10 to be electrically energized via a button 45 so as to provideelectrocautery function to endoscopic cutting forceps 5. Moreparticularly, and looking now at FIGS. 1-3, 5-9 and 12-16 , in thepreferred form of the invention, jaws 10 and support rods 55 are formedout of an electrically conductive material, and button 45 is used toactivate a switch which connects a power line 150 to jaws 10. As aresult, pressing button 45 electrically energizes jaws 10 so as toprovide electrocautery function to endoscopic cutting forceps 5. In thisrespect it should be appreciated that, where shaft 15 is made out of anelectrically conductive material, and/or where drive rod 130 is made outof an electrically conductive material, an insulating member 155 isdisposed between shaft 15 and support rods 55 and jaws 10, and betweendrive rod 130 and support rods 55 and jaws 10, so as to avoidinadvertent short-circuiting of the electrical components of endoscopiccutting forceps 5.

Thus it will be seen that endoscopic cutting forceps 5 generallycomprise a pair of jaws 10 disposed at the distal end of a shaft 15, ablade cutter 20 configured to reciprocate in the space between jaws 10(and hence cut tissue disposed between the pair of jaws 10), and ahandle 25 disposed at the proximal end of shaft 15 for carrying a lever30 for actuating the pair of jaws 10 and a trigger 35 for actuatingblade cutter 20. Endoscopic cutting forceps 5 preferably allow the pairof jaws 10 and blade cutter 20 to be rotated as a unit about the axis ofshaft 15 via a knob 40, and endoscopic cutting forceps 5 preferablyallow the pair of jaws 10 to be electrically energized via a button 45so as to provide electrocautery function to endoscopic cutting forceps5.

Novel Latching Mechanism

In accordance with the present invention, there is also provided a novellatching mechanism for the lever which actuates the jaws, whereby toallow the jaws to be temporarily locked (or clamped) in a closedposition about tissue while the blade cutter is actuated to cut thetissue disposed between the clamped jaws.

Significantly, the latching mechanism of the present invention ismechanically simple and hence easy and inexpensive to manufacture.

In addition, the latching mechanism of the present invention may also beused for the actuating levers of other surgical instruments and/or otherlever-actuated devices wherein the latching mechanism is mechanicallysimple and hence easy and inexpensive to manufacture.

Looking next at FIGS. 1-3, 5-7, 9-11 and 17-26 , there is shown alatching mechanism 200 which comprises one preferred form of the presentinvention. Latching mechanism 200 generally comprises a selector plate205 and a latch plate 210.

Selector plate 205 serves to selectively position latch plate 210 withinhandle 25. Selector plate 205 is movably mounted to handle 25, and latchplate 210 is mounted to selector plate 205, such that, by adjusting theposition of support plate 205 within handle 25, the position of latchplate 210 may also be adjusted within handle 25. In this way selectorplate 205 can be used to selectively position latch plate 210 in a“latch operative position” or in a “latch inoperative position” withinhandle 25, as will hereinafter be discussed.

More particularly, selector plate 205 is slidably mounted to handle 25of endoscopic cutting forceps 5. A thumb button 215 protrudes through awindow 220 formed in handle 25 so that the user can adjustably positionselector plate 205 (and hence adjustably position latch plate 210)within handle 25. Detents 225 are formed in selector plate 205 andcooperate with a protrusion 230 formed on handle 25 whereby to allowselector plate 225 to be maintained in a “latch operative position” orin a “latch inoperative position” within handle 25 until urged otherwiseby the user.

Latch plate 210 is slidably mounted to selector plate 205. Moreparticularly, latch plate 210 comprises a body 235 having a loop spring240 extending therefrom (FIG. 24 ). In one preferred form of theinvention, loop spring 240 is formed integral with body 235. Loop spring240 comprises a bore 245 which is mounted on a pin 250 of selector plate205. Loop spring 240 biases body 235 of latch plate 210 into a givenposition on selector plate 205, but permits body 235 of latch plate 210to be slidably moved on selector plate 205 (both towards and away frompin 250 on selector plate 205) against the power of loop spring 240. Inone preferred form of the invention, latch plate 210 moves linearly withrespect to handle 25 as latch plate 210 moves on selector plate 205.Body 235 of latch plate 210 includes a flange 257 which is slidablymounted on selector plate 205, whereby to stabilize latch plate 210 asit moves on selector plate 205. As a result of this construction, body235 of latch plate 210 can be urged away from pin 250 of selector plate205 against the power of loop spring 240, or body 235 of latch plate 210can be urged toward pin 250 of selector plate 205 against the power ofloop spring 240.

A latch element 255 is mounted to body 235 of latch plate 210. In onepreferred form of the invention, latch element 255 is formed integralwith body 235 of latch plate 210. Latch element 255 comprises a firstsurface 260, a second surface 265, and a third surface 270 (FIG. 26 ).In one preferred form of the invention, first surface 260 comprises asubstantially linear configuration, second surface 265 comprises aconcave configuration, and third surface 270 comprises a slightly convexor substantially linear configuration.

First surface 260, second surface 265 and third surface 270 togetherdefine a labyrinth (i.e., a non-linear track comprising a leading firstsurface 260, a concave second surface 265, and a trailing third surface270, whereby to form a tortuous path with a concavity intermediate itslength), and interact with a latch pin 275 (FIG. 26 ) formed on lever30, so as to provide the desired latching function.

More particularly, when selector plate 205 is appropriately positionedwithin handle 25 so that the apparatus is configured in the “latchoperative position”, and when lever 30 is thereafter pulled toward palmgrip 115 of handle 25 (i.e., so as to close jaws 10), latch pin 275engages first surface 260 of latch element 255 and forces latch plate210 away from pin 250, against the power of loop spring 240. Latch pin275 rides along first surface 260 of latch element 255 until latch pin275 reaches the end of first surface 260, whereupon latch pin 275 movesonto second surface 265 of latch element 255. As soon as latch pin 275moves onto the concave second surface 265, loop spring 240 pulls body235 of latch plate 210 back toward pin 250, until latch pin 275 seats atthe base of concave second surface 265. At this point, lever 30 will bemaintained in this position (i.e., the “latched” position, with jaws 10clamped) until lever 30 is thereafter pulled again. More particularly,when it is thereafter desired to unclamp jaws 10, lever 30 is pulledagain, against the power of loop spring 240, so as to cause latch pin275 to move out of the base of concave second surface 265 of latchelement 255 and further along concave second surface 265. As soon aslatch pin 275 clears the end of concave second surface 265 and movesonto third surface 270 of latch element 255, loop spring 240 pulls latchplate 210 back toward pin 250, until latch pin 275 is returned to itsoriginal starting position clear of third surface 270. At this point,lever 30 will have been returned to its original starting position,pending a further cycling of endoscopic cutting forceps 5.

It will be appreciated that the latching function just described reliesupon the interaction of latch pin 275 with latch element 255. It willalso be appreciated that selector plate 205 allows the position of latchplate 210 to be adjusted within handle 25. Thus selector plate 205provides the ability to render the latching function operative orinoperative by adjusting the position of latch plate 210 (and hence theposition of latch element 255) vis-à-vis the position of lever 30 (andhence the orbit of latch pin 275). More particularly, by positioningselector plate 205 so that the position of latch element 255 is outsidethe orbit of latch pin 275, the selector plate can be used to put theapparatus in a “latch inoperative position”. Conversely, by positioningselector plate 205 so that the position of latch element 255 is withinthe orbit of latch pin 275, the selector plate can be used to put theapparatus in a “latch operative position”. The user adjusts the positionof selector plate 205 using thumb button 215.

Exemplary Operation of the Novel Latching Mechanism of the EndoscopicCutting Force

FIGS. 27-38 illustrate operation of the endoscopic cutting forceps 5(note that the specific constructions shown in FIGS. 27-38 may differslightly from the specific constructions shown in FIGS. 1-26 , however,FIGS. 27-38 depict a common operation of the latching function of thepresent invention). More particularly, FIGS. 27-35 show endoscopiccutting forceps 5 with selector plate 205 set in the “latch operativeposition” and with the apparatus cycling through a completelatching/unlatching operation. FIGS. 36-38 show endoscopic cuttingforceps 5 with selector plate 205 set in the “latch inoperativeposition” and with lever 30 cycling through a complete “pull andrelease” operation.

Alternative Preferred Embodiments

In the preceding description, lever 30 is described as being rotatablypinned to handle 25 at 105. However, it should be appreciated that otherconnections may also be employed. By way of example but not limitation,lever 30 may be movably mounted to handle 25 by the legs of a so-called“4-bar” mechanism.

It should be appreciated that, if desired, selector plate 205 may movein a direction which is different than the direction of movement oflatch plate 210, provided, however, that movement of selector plate 205moves latch plate 210 into, and out of, the orbit of latch pin 275. Byway of example but not limitation, selector plate 205 could move in adirection perpendicular to the direction of movement of latch plate 210,whereby to move latch plate 210 into, and out of, the orbit of latch pin275.

If desired, latch plate 210 may be movably mounted to selector plate 205by a variety of means, so as to provide a variety of differentmovements, e.g., linear movement, pivoting movement, prescribed motionsuch as by a so-called “4-bar” mechanism, traversing in an arcuatetrack, etc.

Thus it will be seen that the present invention provides a new andimproved latching mechanism for an endoscopic cutting forceps whereinthe latching mechanism is mechanically simple and hence easy andinexpensive to manufacture.

It will also be appreciated that the new and improved latching mechanismof the present invention may be used in conjunction with the actuatinglevers of other surgical instruments and/or other lever-actuateddevices, whereby to provide a latching mechanism which is mechanicallysimple and hence easy and inexpensive to manufacture.

Modifications of the Preferred Embodiments

It will be appreciated that various modifications may be made to thepreferred embodiments discussed above without departing from the scopeof the present invention.

Thus, for example, the locations of selector plate 205/latch plate 210and latch pin 275 may be reversed, i.e., selector plate 205 and latchplate 210 may be mounted on lever 30 and latch pin 275 may be mounted onhandle 25.

By way of further example but not limitation, selector plate 205 may beomitted, in which case latch plate 210 is slidably mounted directly tohandle 25 (or, if the location of latch plate 210 and latch pin 275 arereversed, slidably mounted directly to lever 30). Of course, in thisform of the invention, the apparatus is always set in the “latchoperative position” and is incapable of being set in the “latchinoperative position”.

It should be understood that many additional changes in the details,materials, steps and arrangements of parts, which have been hereindescribed and illustrated in order to explain the nature of the presentinvention, may be made by those skilled in the art while still remainingwithin the principles and scope of the invention.

1. (canceled)
 2. A latching system comprising: a first member; a secondmember comprising a latch pin, the second member being movably mountedto the first member so that the latch pin moves in a prescribed motion;a selector plate movably mounted to the first member; a latch platemovably mounted to the selector plate and comprising a labyrinth forselectively receiving the latch pin; and a spring for biasing the latchplate with respect to the selector plate; wherein the selector platemoves the latch plate between an engaged position wherein the labyrinthintersects the prescribed motion and a disengaged position wherein thelabyrinth does not intersect the prescribed motion.
 3. The latchingsystem according to claim 2, wherein the prescribed motion is linearmotion.
 4. The latching system according to claim 2, wherein theprescribed motion is arcuate motion.
 5. The latching system according toclaim 2, wherein the latch plate moves linearly with respect to theselector plate.
 6. The latching system according to claim 2, wherein thelabyrinth comprises a concave surface for seating the latch pin duringlatching, a first surface for engaging the latch pin prior to seating ofthe latch pin in the concave surface, and a second surface for engagingthe latch pin after the latch pin is unseated from the concave surface.7. The latching system according to claim 6, wherein the first surfaceand the second surface are substantially linear.
 8. The latching systemaccording to claim 2, wherein the spring is secured to the selectorplate and engages the latch plate.
 9. The latching system according toclaim 2, wherein the spring is formed integral with the latch plate. 10.The latching system according to claim 2, wherein the spring comprises aleaf spring.
 11. The latching system according to claim 2, wherein thespring comprises a loop spring.
 12. The latching system according toclaim 2, wherein the spring can both extend and compress during movementof the latch plate.
 13. A latching system comprising: a first member; asecond member comprising a latch pin, the second member being movablymounted to the first member so that the latch pin moves in a prescribedmotion; a selector plate movably mounted to the first member; and alatch plate movably mounted to the selector plate and comprising alabyrinth for selectively receiving the latch pin; wherein the selectorplate is operable to move the latch plate between an engaged positionwherein the labyrinth intersects the prescribed motion and a disengagedposition wherein the labyrinth does not intersect the prescribed motion.14. The latching system according to claim 13, wherein the first membercomprises a housing.
 15. The latching system according to claim 14,wherein the second member comprises a lever.
 16. The latching systemaccording to claim 13, wherein the selector plate is movable byactuation of a button, and wherein the button is configured to move theselector plate between a latch operative position and a latchinoperative position.
 17. A latching system comprising: a first member:a second member comprising a latch pin, the second member being movablerelative to the first member so that the latch pin is movable in aprescribed motion; a latch plate comprising a labyrinth for selectivelyreceiving the latch pin, the latch plate positionable relative to thesecond member such that the labyrinth intersects the prescribed motion;and a spring for biasing the latch plate.
 18. The latching systemaccording to claim 17, wherein the first member comprises a housing andthe second member comprises a lever.
 19. The latching system accordingto claim 17, wherein the spring can both extend and compress duringmovement of the latch plate.
 20. The latching system according to claim17, wherein the labyrinth comprises a concave surface for seating thelatch pin during latching, a first surface for engaging the latch pinprior to seating of the latch pin in the concave surface, and a secondsurface for engaging the latch pin after the latch pin is unseated fromthe concave surface.
 21. The latching system according to claim 17,wherein the prescribed motion is arcuate motion.